It looked like Ish Smith had beaten Klay Thompson along the baseline and would jitterbug into the lane for an easy layup.

But Thompson might have just been toying with Smith. The Warriors' shooting guard glided with recovery speed and then extended through the air to swat away Smith's attempt at a reverse layup.

The play Sunday night was a perfect cap on a dominating quarter in which the Warriors allowed Phoenix to score only one field goal for 6 1/2 minutes and forced seven turnovers.

It was also a reminder that the play would not have happened two years ago.

"Klay has made himself a big-time defender," Warriors head coach Mark Jackson said. "He does a great job of guarding the best perimeter guy on the other team. He has size, length and deceptive athletic ability. He pays attention to game-plan discipline, and he's able to get back into the picture with smaller guards and contest shots.

"The amazing thing about it is that he didn't come into the league that way. It's awfully impressive the commitment he's made and how dedicated he is to being a big-time defender."

Thompson will be reunited Tuesday night with one of the first people to impress on him the need to become a better defender when Monta Ellis and the Dallas Mavericks come to Oracle Arena.

Ellis, the scoring dynamo who spent his first 6 1/2 seasons with Golden State, started ahead of Thompson in 2011-12 and consistently overwhelmed the then-rookie during practices. Thompson already had a proven shooting skill that promised to keep him in the league for years, but knew he had to develop his defensive abilities to be considered an elite player.

"He's one of the quickest guys in the NBA, so (playing against him) helped me right away - right when I stepped foot into this league. It was really important," Thompson said. "It's cool playing against him now, because he's still a tough cover."

Ellis was sent to Milwaukee before the trade deadline during Thompson's rookie season - a deal that allowed the Warriors to add a legitimate center in Andrew Bogut and also opened up a starting position for Thompson.

"It's worked out for them," Ellis said. "I always wish them the best."

Just maybe not Tuesday, when Thompson will expect himself to be a different player than Ellis saw his rookie season - one who now can consistently be draped on an opponent and make every shot a difficult one. After replacing the fan-favorite Ellis, Thompson adopted something that hadn't been in his predecessor's job description.

Even with former All-NBA defender Andre Iguodala in the lineup, it's often Thompson who draws the assignment to defend the opponent's best perimeter scorer. He seems to shift effortlessly from guarding quicker point guards to more athletic shooting guards to bigger small forwards - using multiple efforts and a feel for the game.

He does it while maintaining the shooting stroke that got him into the league in the first place. Thompson is averaging a career-best 17.8 points per game and has given glimpses of an improved dribble-drive-and-dish game with personal highs in free-throw attempts and assists.

"The game is easy for Klay," Jackson said. "You get people who say he shouldn't be shooting. Until I leave, he's going to have the light. He's as good a shooter as I've seen. He's a guy who could care less whether he made his last nine or missed his last nine. He's not afraid of the moment.

"He's a guy who gives life to his team with his ability to knock down shots. I played alongside Reggie Miller and saw the impact it had on opposing teams - how it takes the life out of them. They do everything that they could possibly do defensively, and a guy with size, length and ability to shoot the basketball knocks down the shot. Klay is a special player."

On both sides of the ball.

Mavericks (38-26) at Warriors (40-24)

Where: Oracle Arena

When: 7:30 p.m.

TV/Radio: CSNBA/680

Of note: Four of the past five meetings between the Warriors and Mavericks have been decided by fewer than five points, including the first two of this season's four-game series. ... Since a season-worst three-game skid, Dallas has consecutive wins over Portland and Indiana. ... Mavericks forward Dirk Nowitzki needs 13 points to pass John Havlicek (26,395 points) for 12th place on the NBA's all-time list. ... Dallas point guard Jose Calderon is averaging a career-low 1.3 turnovers per game and ranks fourth in the league with a 3.79 assist-to-turnover ratio. ... Dallas is third in the NBA with 8.8 steals per game. The Mavericks have never finished among the league's top three in the category and have been among the top 10 only four times. ... Dallas reserve forward Jae Crowder left Sunday's game with an abdominal strain.